1. Field of the Invention
This invention relates generally to semiconductor products manufacturing, and, more particularly, to a method and apparatus for performing fault model analysis in manufacturing tool operations.
2. Description of the Related Art
The technology explosion in the manufacturing industry has resulted in many new and innovative manufacturing processes. Today""s manufacturing processes, particularly semiconductor manufacturing processes, call for a large number of important steps. These process steps are usually vital, and therefore, require a number of inputs that are generally fine-tuned to maintain proper manufacturing control.
The manufacture of semiconductor devices requires a number of discrete process steps to create a packaged semiconductor device from raw semiconductor material. The various processes, from the initial growth of the semiconductor material, the slicing of the semiconductor crystal into individual wafers, the fabrication stages (etching, doping, ion implanting, or the like), to the packaging and final testing of the completed device, are so different from one another and specialized that the processes may be performed in different manufacturing locations that contain different control schemes.
Among the important aspects in semiconductor device manufacturing are rapid thermal anneal (RTA) processing control, chemical-mechanical polishing (CMP) control, and overlay control. The RTA process involves rapidly heating a semiconductor wafer in order to repair the silicon crystal lattice of the semiconductor device. Generally, the total energy transferred to the wafer is important because it affects ion concentration in the semiconductor device. The ion concentration in the semiconductor device affects the electrical properties of the semiconductor device. Currently, process control of rapid thermal processes includes resistivity test wafers that are run on a predetermined frequency and wafer electrical test (WET) measurements made on product wafers.
Changes in processing tools, or in the process itself, can greatly impact final device quality. However, processing tool changes and process changes can be difficult to detect using current control techniques. Furthermore, using current control techniques, detecting processing tool changes and process changes is difficult to perform without jeopardizing a large amount of product wafers.
Generally, an RTA process tool processes semiconductor wafers on an individual basis. An equipment interface (not shown) is used by an Manufacturing Execution System (MES) to control the RTA process tool. The equipment interface is also connected to a process control system, such as the Advanced Process Control (APC) framework, to allow the APC system to collect real-time trace data from the RTA process tool. Furthermore, the APC system is capable of interrupting processing of semiconductor wafers when necessary. The current system of checking for error on product of sample wafer and making correction can cause inefficiencies and errors in the manufactured semiconductor devices.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.
In one aspect of the present invention, a method is provided for fault model analysis in manufacturing tools. A sequence of semiconductor devices is processed through a manufacturing process. Production data resulting from the processing of the semiconductor devices is acquired. A fault model analysis is performed using the acquired production data.
In another aspect of the present invention, an apparatus is provided for fault model analysis in manufacturing tools. The apparatus of the present invention comprises: means for processing a sequence of semiconductor devices through a manufacturing process; means for acquiring production data resulting from the processing of the semiconductor devices; and means for performing a fault model analysis using the acquired production data.